Chassis shipping unit

ABSTRACT

A chassis shipping unit for over-the-road trailer chassis. The shipping unit includes a base platform for supporting first and second trailer chassis; first tandem leg structure mounted to the base platform for extending upward between the leading and trailing wheels of the first trailer chassis; and second tandem leg structure mounted to the base platform for extending upward between the leading and trailing wheels of a second trailer chassis with the second trailer chassis supported above the first trailer chassis.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to a unit for use in shippingcontainer chassis, and more particularly to a collapsible chassisshipping unit for multiple container chassis.

2. Background Art

In the intermodal transportation industry, goods are often shipped inlarge box-like containers, commonly referred to as “ISO (InternationalStandardization Organization) containers,” that have standardizedfittings at standardized locations to receive standardized twist locksand locking pins, etc. Such ISO containers are commonly transported byship, rail, and road. For transport, the ISO containers are commonlylocked to flat bed trailers (typically referred to as “container ortrailer chassis”) for being pulled by tractors, etc., from a loadinglocation to an off-loading location. Often times the trailer chassiswill need to be transported back to a loading or storage locationwithout a load (i.e., empty). Such transport of empty trailer chassisadds to the expense of intermodal transportation, and various methodsand structures have been developed to allow several empty trailerchassis to be transported as a single unit or bundle to a loading orstorage location, etc. See, for example, Braly et al., U.S. Pat. No.4,611,962, issued Sep. 16, 1986, which discloses a container chassisbundling system in which a stack of empty trailer chassis are placed ontop of another trailer chassis and secured thereto using thestandardized twist locks, etc., and with a lifting frame connected tothe upper trailer chassis in the bundle so that the entire bundle can belifted as a bundle.

Nothing in the know prior art discloses or suggests the presentinvention.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to an improved chassis shipping unit forsafely and securely accommodating a plurality of over-the-road trailerchassis.

The chassis shipping unit of the present invention is for accommodatingover-the-road trailer chassis of the type including a tandem supportwheel assembly having a leading wheel and a trailing wheel spaced fromthe leading wheel. The chassis shipping unit includes base platformmeans for supporting first and second trailer chassis with the secondtrailer chassis supported above the first trailer chassis; first tandemleg means mounted to the base platform means for extending upwardbetween the leading and trailing wheels of the first trailer chassiswhen the first trailer chassis is supported on the base platform means;and second tandem leg means mounted to the base platform means forextending upward between the leading and trailing wheels of the secondtrailer chassis when the second trailer chassis is supported on the baseplatform means.

It is an object of the present invention to provide a chassis shippingunit that will handle both 40 foot (12.2 meters) and 20 foot (6.1meters) container chassis on the same unit, without modification.

It is a further object of the present invention to provide such achassis shipping unit that has the ability to be folded flat, stacked ingroups of four, and mounted on a road chassis while staying within thehighway legal load height limit (typically 13 feet, 6 inches, or 4.1meters).

It is a further object of the present invention to provide such achassis shipping unit that can be locked together in stacks of fourfolded units with interbox connectors and ship this “bundle” atop a roadchassis, a rail flat car, or a container which is loaded into awell-car.

It is a further object of the present invention to provide such achassis shipping unit that has the ability to stack multiple loadedunits atop one another for stationary storage to allow significantsavings of space as compared with parking individual chassis on theground.

It is a further object of the present invention to provide such achassis shipping unit that has the ability to lock stacked and loadedunits together securely to assure a stable stack, not subject to havingthe upper units slide off the lower ones.

It is a further object of the present invention to provide such achassis shipping unit that uses eight legs, each of which fold 90°, withfour of these legs folding outward while the other four fold inward.

It is a further object of the present invention to provide such achassis shipping unit in which four of the legs serve as chassislocating members to prevent chassis movement either for-and-aft orside-to-side. These legs can be designated as “tandem legs” and foldaway from each other along the longitudinal unit axis.

It is a further object of the present invention to provide such achassis shipping unit that has four chassis locating (tandem) legs,located to provide for optimum nesting of both 20 foot and 40 footchassis. These tandem legs fold toward each other, along the unit'slongitudinal axis.

It is a further object of the present invention to provide such achassis shipping unit that has four additional legs known as “ISO”(International Standards Organization) legs, positioned on a standard“ISO 20 foot pattern” to allow for lifting the unit either loaded orempty via the use of a standard top-pick container spreader.

It is a further object of the present invention to provide such achassis shipping unit in which the main frame members have a built-in“camber” or bow, as viewed from the side of the unit, to prevent thebottom of the frame members from slapping against the top of a containerwhen the unit is shipped atop a container.

It is a further object of the present invention to provide such achassis shipping unit that uses tension spring assemblies forcounterbalancing the weight of each leg during the folding operation.

It is a further object of the present invention to provide such achassis shipping unit in which counterbalance spring assemblies allowunassisted one-person manual operation for folding and unfolding thelegs.

It is a further object of the present invention to provide such achassis shipping unit in which tension type counterbalance springassemblies provide virtually uniform force on each leg for folding.

It is a further object of the present invention to provide such achassis shipping unit in which tension spring adjustment bolts allow thespring force to be set to the proper level to obtain the desired manualforce for raising or lowering the legs, and allow compensation forvariance in the weights of the ISO legs and the tandem legs.

It is a further object of the present invention to provide such achassis shipping unit that uses cable assemblies wrapping around aradiused portion of each leg base, instead of conventional linkages, tohelp provide uniform forces when raising or lowering the legs.

It is a further object of the present invention to provide such achassis shipping unit that has commercial trailer tie-down winches andstraps strategically positioned to secure each load whether 20 foot or40 foot chassis.

It is a further object of the present invention to provide such achassis shipping unit that includes transverse, folding chassis supportarms to hold the forward end of 20 foot chassis frames, preventingbouncing during transit.

It is a further object of the present invention to provide such achassis shipping unit that includes either leg hold-down chains whichattach to the main frame when the legs are folded down, or mating bossand pin-type lock means, to prevent the legs from bouncing.

It is a further object of the present invention to provide such achassis shipping unit that includes manually folding leg locks to securethe legs in the upright, operating position and to prevent movementduring transit or severe braking.

It is a further object of the present invention to provide such achassis shipping unit that includes secondary gravity-assisted latchesto prevent the leg locks form opening up during sever bumps.

A general purpose of the present invention to provide a safe, efficientmeans to transport multiple 20 foot or 40 foot container chassis viaeither highway or rail.

Another general purpose of the present invention to transport such unitswhile empty in “bundles” of four securely attached to each other, and tothe transporting unit, whether on a road chassis, a rail car, or atop acontainer which is being carried in a rail well-car.

Another general purpose of the present invention to save chassis yardstorage space by stacking multiple units atop one another for stationarystorage.

Another general purpose of the present invention to prevent containertop damage during shipment of one of the chassis shipping unit.

Another object of the present invention is to provide a chassis shippingunit in which all means of locating and securing the chassis are builtinto the unit so there is no loose gear subject to loosening, fallingoff, or becoming lost.

Another object of the present invention is to provide a chassis shippingunit which is self-locating and easily secured by either ISO pins orattached tie-down straps located to provide the most efficient, safesecurement for all chassis.

Another object of the present invention is to provide a chassis shippingunit which can be easily folded flat and locked to other units andsecured four in a bundle that will be within legal highway load heightsfor over-the-road shipment.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an exploded elevational view showing a left side elevation ofthe chassis shipping unit of the present invention in combination withfour 40 foot long over-the-road trailer chassis to be held by thechassis shipping unit, and a 40 foot long over-the-road trailer chassisto support the chassis shipping unit.

FIG. 2 is an exploded elevational view similar to FIG. 1 but showing aright side elevation of the chassis shipping unit of the presentinvention in combination with three 20 foot long over-the-road trailerchassis to be held by the chassis shipping unit, and a 40 foot longover-the-road trailer chassis to support the chassis shipping unit.

FIG. 3 is an elevational view of the components of FIG. 1 showing theleft side of the chassis shipping unit of the present inventionsupported on the 40 foot long over-the-road trailer chassis, and holdingthe four 40 foot long over-the-road trailer chassis.

FIG. 4 is an elevational view of the components of FIG. 2 showing theleft side of the chassis shipping unit of the present inventionsupported on the 40 foot long over-the-road trailer chassis, and holdingthe three 20 foot long over-the-road trailer chassis.

FIG. 5 is an elevational view of the components of FIG. 1 similar toFIG. 3 but showing the right side of the chassis shipping unit of thepresent invention supported on the 40 foot long over-the-road trailerchassis, and holding the four 40 foot long over-the-road trailerchassis.

FIG. 6 is an elevational view of the components of FIG. 2 similar toFIG. 4 but showing the right side of the chassis shipping unit of thepresent invention supported on the 40 foot long over-the-road trailerchassis, and holding the three 20 foot long over-the-road trailerchassis

FIG. 7 is a perspective view of the chassis shipping unit of the presentinvention.

FIG. 8 is a somewhat diagrammatic sectional view substantially as takenon line 8-8 of FIG. 3 and rotated 90°.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of the chassis shipping unit of the presentinvention is shown in FIGS. 1-8 and identified by the numeral 11. Thechassis shipping unit 11 is used to accommodate (i.e., carry and/orstore) at least one and preferably multiple over-the-road trailerchassis 13.

The chassis 13 are preferably of the type including generally flat baseor bed 15 with various ISO twistlocks and the like for supporting andsecuring a load such as one or more ISO containers, a tandem supportwheel assembly 17 located generally toward the rear of the bed 15, ahitch means 19 located generally at the front or gooseneck of the bed 15to allow connection to a coacting hitch means of a standardover-the-road tractor or truck, and landing gear support leg means 21located generally toward the front of the bed 15 for supporting thefront of the bed 15 when the bed 15 is not connected to theover-the-road tractor or truck, etc. The tandem support wheel assembly17 typically has a leading right-side wheel 23 and a trailing right-sidewheel 25 spaced from the leading right-side wheel 23, and has a leadingleft-side wheel 27 and a trailing left-side wheel 29 spaced from theleading left-side wheel, as will now be apparent to those skilled in theart. The chassis 13 also typically includes standardized twist locks 31or the like attached to the top of the bed 15 for coacting with coactingstandardized twist locks or the like of ISO containers, etc., to securesuch ISO containers, etc., to the chassis 13 as will now be apparent tothose skilled in the art. Such chassis 13 are commonly available in twosizes, a 40 foot (12.2 meters) size for supporting a 40 foot (12.2meters) ISO container, and a 20 foot (6.1 meters) size for supporting a20 foot (6.1 meters) ISO container. The construction and use of suchchassis 13 are well know to those skilled in the art. The chassisshipping unit 11 of the present invention is specially adapted tosupport up to four chassis 13 of the 40 foot size (see FIGS. 1, 3 and 5)and up to three chassis 13 of the 20 foot size (see FIGS. 2, 4 and 6).

The chassis shipping unit 11 includes a base platform or frame means 31for supporting at least a first trailer chassis 13 and a second trailerchassis 13 with the second trailer chassis 13 supported above the firsttrailer chassis 13. The base frame means 31 may be used to support astack of four 40 foot chassis 13 as clearly shown in FIGS. 1, 3 and 5,or a stack of three 20 foot chassis 13 as clearly shown in FIGS. 2, 4and 6. The base frame means 31 is preferably an open structural platformincluding elongated left and right side beams 33 joined by a pluralityof cross beams 35 (see FIG. 7). The side beams 33 may be I-beams and thecross beams 37 may be box tubing or the like. Two of the cross beams 35may be accessible through the side beams 33 via openings 37 or the likefor allowing the chassis shipping unit 11 to be easily lifted and moved,etc., using a, standard fork lift truck and the like. Diagonallyextending beams, plates and angle members are preferably provided tostrengthen the base platform means 31 as will now be apparent to thoseskilled in the art.

The base platform 31 has a bottom surface 39 formed or defined by thebottom surfaces of the side beams 33, and cross beams 35, 37, etc., witha front end 41, a rear end 43, and a midportion 45 between said frontand rear ends 41, 43 with the midportion 45 bowed upward when chassis 13are not supported thereon (see FIGS. 1 and 2) thereby provide an unladenchassis shipping unit 11 with a built in camber or bow to provideapproximately 2 inches (5.08 centimeters) of clearance above whateverthe base platform means 31 may be supported on (e.g, an ISO container,the deck of a ship, the floor of a train car or flatbed truck, or a 40foot chassis C) at the center of the midportion 45 to prevent the bottomsurface 39 from slapping against the top of a ISO container or the likeif an unladen chassis shipping unit 11 is shipped on top of such a ISOcontainer, etc.

The chassis shipping unit 11 includes first or front tandem leg means 47mounted to the base platform means 31 for extending upward between theleading and trailing wheels 23, 25, 27, 29 of one or more chassis 13when the chassis 13 are supported on said base platform means 31.Likewise, the chassis shipping unit 11 incudes second or rear tandem legmeans 49 mounted to the base platform means 31 for extending upwardbetween the leading and trailing wheels 23, 25, 27, 29 of one or morechassis 13 when the chassis 13 are supported on said base platform means31. The first and second tandem leg means 47, 49 are preferablypivotally mounted to said base platform means 31 via pivot rods 51 orthe like for movement between substantially vertical, in-use positionsand substantially horizontal, stored positions. The tandem leg means 47,49 are preferably designed to pivot or fold outward, away from eachanother along the longitudinal axis of the base platform means 31. Eachtandem leg means 47, 49 preferably includes a right side tandem legmember 53 pivotally attached to the right side beam 33 of the baseplatform means 31 via a pivot rod 51, and a left side tandem leg member55 pivotally attached to the left side beam 33 of the base platformmeans 31 via a pivot rod 51. Each tandem leg member 53, 55 may beconstructed from elongated steel box beam members. The four tandem legmembers 53, 55 provide means to properly locate the chassis 13 on thebase platform means 31. By extending upward between adjacent leading andtrailing wheels 23, 25 or 27, 29, the tandem leg members 53, 55 not onlyserve to insure proper location of the various chassis 13 on the baseplatform means 31, but also serve to prevent or limit both fore-and-aftand side-to-side movement of the chassis 13 as will now be apparent tothose skilled in the art. The four tandem leg members 53, 55 arepreferably positioned to provide for optimum nesting of both 20 foot and40 foot chassis 13.

The chassis shipping unit 11 preferably includes first or front lift legmeans 57 mounted to the base platform means 31 rearward of the firsttandem leg means 47, and a second or rear lift leg means 59 mounted tothe base platform means 31 forward of the second tandem leg means 49.The first and second lift leg means 57, 59 are preferably pivotallymounted to said base platform means 31 via pivot rods 61 or the like formovement between substantially vertical, in-use positions andsubstantially horizontal, stored positions. The lift leg means 57, 59are preferably designed to pivot or fold inward, toward one anotheralong the longitudinal axis of the base platform means 31. Each lift legmeans 57, 59 preferably includes a right side lift leg member 63pivotally attached to the right side beam 33 of the base platform means31 via a pivot rod 61, and a left side lift leg member 65 pivotallyattached to the left side beam 33 of the base platform means 31 via apivot rod 61. Each lift leg member 63, 65 may be constructed fromelongated steel box beam members, positioned on a standard ISO 20 footpattern, and preferably has a ISO twist-lock lift connection 67 or thelike (see FIG. 7) attached to the top end thereof for allowing thechassis shipping unit 11 to be used with a standard lifting device,i.e., to be lifted, either loaded or empty, via the use of a standardtop-pick container spreader as will now be apparent to those skilled inthe art.

Counterbalanced springs (not shown) may be provided for allowing theoperator of the chassis shipping unit 11 to raise and lower the legmembers 53, 55, 63, 65 without any need for additional power equipmentor the like.

The chassis shipping unit 11 preferably includes strap means 69 forstrapping the trailer chassis 13 to said base platform means 31. Thestrap means 69 preferably includes three spaced apart strap winches 71attached to each side beam 33 of the base platform means 31, and anelongated woven fabric tie-down strap 73 associated with each winch 71for securely tieing the chassis 13 down on the base platform means 31during shipment, etc. These strap means 69 are the type commonly foundon commercial flatbed trailers for securing cargo via the use ofmultiple straps. The winches 71 are typically manually operated with theuse of elongated bar-like handles or the like (not shown).

Two-piece folding cross braces 75 may be provided between the legmembers 63, 65 of the first or forward lift leg means 57 (see FIGS. 4and 7) for supporting the bed 15 of a third 20 foot chassis 13 whenthree 20 foot chassis 13 are mounted on the chassis shipping unit 11 asshown in FIG. 4.

Interbox connectors 77 may be provided (see FIG. 7) for allowing empty,folded chassis shipping units 11 to be connected together for shipping.

Pads 79 may be provided on the base platform means 31 on which thetrailing wheels 25, 29 of a second chassis 13 will rest when mounted onthe chassis shipping unit 11 above a first chassis 13.

Female ISO sockets 81 are preferably mounted on the forward corners andmidway along the length of each side beam 33 of the base platform means31 for engaging coacting ISO twistlock pins of the first loaded chassis13.

Land gear support plates 83 are preferably provided on the base platformmeans 31 (see FIG. 7) for supporting the landing gear 21 of the firstchassis 13.

To load or mount a plurality of chassis 13 on the chassis shipping unit11, the tandem leg means 47, 49 and lift leg means 57, 59 are allpositioned in the raised or vertical, in-use positions.

To load three 20 foot chassis 13 on the chassis shipping unit 11 (seeFIGS. 2, 4 and 6), the landing gear 21 of the first or lowermost chassis13 is fully retracted, and, using a fork lift or the like, that first orlowermost chassis 13 is inverted and placed with its tandem supportwheel assembly 17 toward the front of the base platform means 31. Thatfirst or lowermost chassis 13 is then lowered with its leading andtrailing wheels 23, 25, 27, 29 straddling the respective leg members 53,55 of the front tandem leg means 47, until it rest on the base platformmeans 31 with all four of the ISO twistlock pins of the chassis 13engaging respective ISO sockets 81 on the base platform means 31. Thetwistlock pins can then be locked in a manner now apparent to thoseskilled in the art to secure that chassis 13 to the base platform means31. Again using a fork lift or the like, a second or middle chassis 13is lowered in an upright or non-inverted position over the rear of thebase platform means 31 with the leading and trailing wheels 23, 25, 27,29 of its tandem support wheel assembly 17 straddling the respectivelegs members 53, 55 of the rear tandem leg means 49, until its tandemsupport wheel assembly 17 and landing gear 21 come to rest on therespective pads 79 and plates 83. The landing gear 21 of the second ormiddle chassis 13 can then be adjusted (raised or lowered) so that itsframe just clears the frame of the first or lower chassis 13. Thefolding cross braces 75 on the front lift leg means 57 are then openedto provide a support beam between the leg members 63, 65 as shown inFIG. 7, and the landing gear 21 of a third or uppermost chassis 13 isfully retracted, and, using a fork lift or the like, that third oruppermost chassis 13 is inverted and placed with its tandem supportwheel assembly 17 toward the front of the base platform means 31. Thatthird or uppermost chassis 13 is then lowered with its leading andtrailing wheels 23, 25, 27, 29 straddling the respective leg members 53,55 of the front tandem leg means 47, until its main frame comes to restatop the main frame of the second or middle chassis 13 and the rearportion of its main frame comes to rest on the cross braces 75. Straps73 of the forward two strap means 69 are then toss over the top of thethird or uppermost chassis 13, and the strap 73 of the rearward strapmeans 69 is toss over the second or middle chassis 13. The straps 73 areconnected to the respective winches 71 and tightened until all thechassis 13 are secure. The load is then ready for shipping, etc.

To load four 40 foot chassis 13 on the chassis shipping unit 11 (seeFIGS. 1, 3 and 5), the landing gears 21 of the first or lowermostchassis 13, the third or upper middle chassis 13, and the fourth oruppermost chassis 13 are fully retracted. Then, using a fork lift or thelike, that first or lowermost chassis 13 is inverted and placed with itstandem support wheel assembly 17 toward the rear of the base platformmeans 31. That first or lowermost chassis 13 is then lowered with itsleading and trailing wheels 23, 25, 27, 29 straddling the respective legmembers 53, 55 of the rear tandem leg means 49, until it rest on thebase platform means 31 with the rear pair of ISO twistlock pins of thechassis 13 engaging respective ISO sockets 81 on the base platform means31. The twistlock pins can then be locked in a manner now apparent tothose skilled in the art to secure that chassis 13 to the base platformmeans 31. The forward horizontal chassis pins of the first chassis 13should engage a front pair of holes in the front end of the baseplatform means 31. Again using a fork lift or the like, the second orlower middle chassis 13 is lowered in an upright or non-invertedposition onto the base platform means 31 with the leading and trailingwheels 23, 25, 27, 29 of its tandem support wheel assembly 17 straddlingthe respective legs members 53, 55 of the front tandem leg means 47,until its tandem support wheel assembly 17 and landing gear 21 come torest on the respective pads 79 and plates 83. The landing gear 21 of thesecond or middle chassis 13 can then be adjusted (raised or lowered) sothat its frame just clears the axles, suspension and brake chambers ofthe first chassis 13. Again using a fork lift or the like, the third orupper middle chassis 13 is inverted with its tandem support wheelassembly 17 toward the rear of the chassis shipping unit 11. That thirdchassis 13 is lowered onto the base platform means 31 with the leadingand trailing wheels 23, 25, 27, 29 of its tandem support wheel assembly17 straddling the respective legs members 53, 55 of the rear tandem legmeans 49, until the front, gooseneck portion of its main frame comes torest atop the main frame of the second or lower middle chassis 13, andthe rear portion of its main frame comes to rest on the gooseneckportion of the second or lower middle chassis 13. Again using a forklift or the like, the fourth or upper chassis 13 is lowered in anupright or non-inverted position with its tandem support wheel assembly17 toward the front of the chassis shipping unit 11 and with the leadingand trailing wheels 23, 25, 27, 29 of its tandem support wheel assembly17 straddling the respective legs members 53, 55 of the front tandem legmeans 47, until its tires come to rest atop the tires of the second orlower middle chassis 13 and its landing gear 21 comes to rest atop thelanding gear housing of the second or lower middle chassis 13. Thelanding gear 21 of the fourth or upper chassis 13 can then be adjustedin height so the frame of the fourth or upper chassis 13 just clears theaxles, suspension and brake chambers of the third or upper middlechassis 13. Straps 73 of the strap means 69 are then tossed over the topof the fourth or uppermost chassis 13. The straps 73 are connected tothe respective winches 71 and tightened until all the chassis 13 aresecure. The load is then ready for shipping, etc.

Although the present invention has been described and illustrated withrespect to preferred embodiments and preferred uses therefor, it is notto be so limited since modifications and changes can be made thereinwhich are within the full intended scope of the invention.

1. A chassis shipping unit for accommodating over-the-road first andsecond trailer chassis, each of the trailer chassis including a tandemsupport wheel assembly having a leading wheel and a trailing wheelspaced from the leading wheel; said chassis shipping unit comprising:(a) base platform means for supporting the first and second trailerchassis with the second trailer chassis supported above the firsttrailer chassis; (b) first tandem leg means mounted to said baseplatform means for extending upward between the leading and trailingwheels of the first trailer chassis when the first trailer chassis issupported on said base platform means; and (c) second tandem leg meansmounted to said base platform means for extending upward between theleading and trailing wheels of the second trailer chassis when thesecond trailer chassis is supported on said base platform means.
 2. Thechassis shipping unit of claim 1 in which said chassis shipping unit isfor use with a lift device, and in which included spaced apart first andsecond lift leg means mounted to said base platform means for allowingsaid chassis shipping unit to be lifted by the lift device.
 3. Thechassis shipping unit of claim 1 in which said base platform includes abottom surface having a front end, a rear end, and a midportion betweensaid front and rear ends; and in which said midportion of said bottomsurface of said base platform is bowed upward.
 4. The chassis shippingunit of claim 1 in which in which said first and second tandem leg meansare pivotally mounted to said base platform means for movement betweenan in-use position and a stored position.
 5. The chassis shipping unitof claim 2 in which said first and second lift leg means are pivotallymounted to said base platform means for movement between an in-useposition and a stored position
 6. The chassis shipping unit of claim 1in which is included strap means for strapping the trailer chassis tosaid base platform means.
 7. A chassis shipping unit for use with a liftdevice and for accommodating over-the-road first, second, third andfourth trailer chassis, each of the trailer chassis including a tandemsupport wheel assembly having a right side leading wheel and a rightside trailing wheel spaced from the right side leading wheel, and havinga left side leading wheel and a left side trailing wheel spaced from theleft side leading wheel; said chassis shipping unit comprising: (a) baseplatform means for supporting the first, second, third and fourthtrailer chassis with the second trailer chassis supported above thefirst trailer chassis, with the third trailer chassis supported abovethe second trailer chassis, and with the fourth trailer chassissupported above the third trailer chassis; said base platform meanshaving a front, a rear, a right side, and a left side; (b) first tandemleg means mounted to said base platform means adjacent said frontthereof for extending upward between the leading and trailing wheels ofthe first and third trailer chassis when the first and third trailerchassis are supported on said base platform means; said first tandem legmeans including a right side first tandem leg for extending upwardbetween the right side leading and trailing wheels of the first andthird trailer chassis when the first and third trailer chassis aresupported on said base platform means; said first tandem leg meansincluding a left side first tandem leg for extending upward between theleft side leading and trailing wheels of the first and third trailerchassis when the first and third trailer chassis are supported on saidbase platform means; (c) second tandem leg means mounted to said baseplatform means adjacent said rear thereof for extending upward betweenthe leading and trailing wheels of the second and fourth trailer chassiswhen the second and fourth trailer chassis are supported on said baseplatform means; said second tandem leg means including a right sidesecond tandem leg for extending upward between the right side leadingand trailing wheels of the second and fourth trailer chassis when thesecond and fourth trailer chassis are supported on said base platformmeans; said second tandem leg means including a left side second tandemleg for extending upward between the left side leading and trailingwheels of the second and fourth trailer chassis when the second andfourth trailer chassis are supported on said base platform means; (d)first lift leg means mounted to said base platform means adjacent saidfront thereof; said first lift leg means including a right side firstlift leg mounted adjacent said right side of said base platform and aleft side first lift leg mounted adjacent said left side of said baseplatform; and (e) second lift leg means mounted to said base platformmeans adjacent said rear thereof and spaced from said first lift legmeans for coacting with said first lift leg means to allow said chassisshipping unit to be lifted by the lift device; said second lift legmeans including a right side second lift leg mounted adjacent said rightside of said base platform and a left side second lift leg mountedadjacent said left side of said base platform.
 8. The chassis shippingunit of claim 7 in which said base platform includes a bottom surfacehaving a front end, a rear end, and a midportion between said front andrear ends; and in which said midportion of said bottom surface of saidbase platform is bowed upward.
 9. The chassis shipping unit of claim 7in which said first and second tandem legs are pivotally mounted to saidbase platform means for movement between an in-use position and a storedposition; and in which said first and second lift legs are pivotallymounted to said base platform means for movement between an in-useposition and a stored position.
 10. The chassis shipping unit of claim 7in which is included strap means for strapping the trailer chassis tosaid base platform means.
 11. In combination, a chassis shipping unit,an over-the-road first trailer chassis, an over-the-road second trailerchassis, an over-the-road third trailer chassis, and an over-the-roadfourth trailer chassis; said chassis shipping unit comprising: (a) baseplatform means supporting the first, second, third and fourth trailerchassis with the second trailer chassis supported above the firsttrailer chassis, with the third trailer chassis supported above thesecond trailer chassis, and with the fourth trailer chassis supportedabove the third trailer chassis; said base platform means having afront, a rear, a right side, and a left side; (b) first tandem leg meansmounted to said base platform means adjacent said front thereof andextending upward between the leading and trailing wheels of the firstand third trailer chassis; said first tandem leg means including a rightside first tandem leg extending upward between the right side leadingand trailing wheels of the first and third trailer chassis; said firsttandem leg means including a left side first tandem leg extending upwardbetween the left side leading and trailing wheels of the first and thirdtrailer chassis; (c) second tandem leg means mounted to said baseplatform means adjacent said rear thereof and extending upward betweenthe leading and trailing wheels of the second and fourth trailerchassis; said second tandem leg means including a right side secondtandem leg extending upward between the right side leading and trailingwheels of the second and fourth trailer chassis; said second tandem legmeans including a left side second tandem leg extending upward betweenthe left side leading and trailing wheels of the second and fourthtrailer chassis; (d) first lift leg means mounted to said base platformmeans adjacent said front thereof; said first lift leg means including aright side first lift leg mounted adjacent said right side of said baseplatform and a left side first lift leg mounted adjacent said left sideof said base platform; and (e) second lift leg means mounted to saidbase platform means adjacent said rear thereof and spaced from saidfirst lift leg means for coacting with said first lift leg means toallow said chassis shipping unit to be lifted by the lift device; saidsecond lift leg means including a right side second lift leg mountedadjacent said right side of said base platform and a left side secondlift leg mounted adjacent said left side of said base platform.
 12. Thechassis shipping unit of claim 11 in which is included strap meansstrapping the trailer chassis to said base platform means.